In-Situ Synthesis and Formation Mechanism of Al2 3-Spinel
3-spinel(N) composite. The mechanism for formation of the spinel(N) can be described as follows in nitrogen atmosphere with low oxygen partial pressure magnesia is unstable and decomposes into Mg(g). Mg(g) diffuses and transfers along the pores or gaps in Al 2O 3-MgO composites and reacts with corundum or spinel forming gas aluminum at the
Get PriceSpinel In situ versus PreformedClearing the Myth
The spinel forming castable contains 5 dead burnt magnesia ≤90 µm thus leading to a theoretical spinel formation of 22 . In practical applications a combination of spinel formation with pre-reacted spinel is also widely used. The two remaining cast-ables belong to this group of products one with an ultra low cement bond (SP-SF) and
Get PriceCORROSION MECHANISM OF SPINEL FORMING AND SPINEL
corrosion mechanisms going on in steel plant and in lab conditions monolithic lance for argon and powder aditions blowing was cast using the same ULC95TA-MgO (DBM) spinel forming castable. The lance was then exposed to plant corrosion conditions during service. It
Get PriceCET CorrosionForms of Corrosion
Nov 07 2018 · This corrosion can take many forms and can be controlled by biocides or by conventional corrosion control methods. There are a number of mechanisms associated with this form of corrosion and detailed explanations are available at the web sites listed at the bottom of this section.
Get PriceModelling of the oxide scale formation on Fe‐Cr steel
Jan 12 2011 · Previous studies showed that the oxidation of T91 (Fe‐9Cr martensitic steel) in liquid Pb‐Bi eutectic leads to the formation of a duplex oxide layer containing an inner Fe 2.3 Cr 0.7 O 4 spinel layer and an upper magnetite layer. The magnetite layer is easily removed by the Pb‐Bi flow when the oxygen concentration is low and the flow velocity is high.
Get PriceCorrosion of MgO-C with Magnesium Aluminate Spinel
Fundamental investigations of the corrosion mechanism of MgO-MgAl 2 O 4-C refractories for application in steel ladles are not available so far.For the properties of MgO-MgAl 2 O 4-C refractories the chemical composition of the spinel raw material is essential.Hence the aim of this paper is to describe the influence of two common coarse-grained spinel raw materials on the corrosion mechanism
Get PriceSpinel In situ versus PreformedClearing the Myth
The spinel forming castable contains 5 dead burnt magnesia ≤90 µm thus leading to a theoretical spinel formation of 22 . In practical applications a combination of spinel formation with pre-reacted spinel is also widely used. The two remaining cast-ables belong to this group of products one with an ultra low cement bond (SP-SF) and
Get PriceCorrosion of MgO-C with Magnesium Aluminate Spinel
react with magnesia forming a spinel which decreases open porosity and slag infiltration. The amount grain size and chemistry of the added spinel impact the properties of spinel-containing MgO-C. Corrosion tests have been performed in a steel casting simulator at 1580 C using 18CrNiMo7-6 steel and Fe-rich slag as corrosion medium.
Get PriceMechanism of metal dusting corrosion by pitting of a
Mechanism of metal dusting corrosion by pitting of a chromia-forming alloy at atmospheric pressure and low gas velocity. (2016) Corrosion Science vol. 107. pp. . ISSN X Any correspondence concerning this service should be sent to the repository administrator staff-oatao listes-diffp-toulouse.fr
Get PriceReaction behavior of slag and spinel in steel ladle castables
The difference in corrosion behavior between alumina-spinel and alumina-magnesia castables in a steel slag was investigated with emphasis on the composition of spinel phase. The spinel primarily-added to the alumina-spinel castable had the 3.2 Mechanism of spinel formation in A-M casta-
Get PriceAbstract No. gao416 Characterization of Corrosion Oxides
(spinel structure) that form on alloys have a tendency to incorporate radioactive cobalt circulating in the reactor coolant. To fully understand the corrosion mechanism and to evaluate the effectiveness of potential fixes it is of importance to determine the chemistry of spinel phase as a function of water conditions. In this work only
Get PriceCorrosion of high alumina spinel castables by steel ladle
Jul 18 2013 · The application of high alumina materials with additions of spinel and/or spinel forming magnesia as wear linings in steel ladles has increased in recent years. Corrosion of high alumina spinel castables by steel ladle slag The influences of mechanical properties and chemical composition on the wear mechanism are discussed. Although the
Get PriceCorrosion Behavior of Stainless Steels in Simulated PWR
sition influence both SCC susceptibility and corrosion be-havior the mechanism of SCC is considered to be inevitably related to corrosion behavior. Some of the authors conducted microstructural analysis on crack tips of SCC in simulated PWR primary water.9) The crack tips were filled with chro-mium-rich spinel oxide. The morphology of the
Get PriceThe corrosion of refractory castables Request PDF
Experiments on the corrosion of alumina based refractory castables containing 1 2 5 and 10 mass- of cement and 10 mass- of spinel were conducted in an induction furnace at 1550 1650 and
Get PriceCORROSION-INHIBITIVE EFFECTS OF SPINEL TYPE PIGMENTS
represented by the corrosion of steel plate in clean distilled water. The results given in Table 4 show clearly different efficiencies of the spinel pigments investigated. It is of course necessary to consider that these results inform only on the part of potential inhibition mechanism of anticorrosive spinel
Get PriceFundamentals and applications on in situ spinel formation
Whereas the in situ spinel (MgAl2O4) formation provides an enhanced corrosion and thermal-shock resistance to the castable the composition with pre-formed grains shows higher volumetric stability
Get PriceSpinel groupWikipedia
The space group for a spinel group mineral may be Fd 3 m (the same as for diamond) but in some cases (such as spinel itself MgAl 2 O 4) it is actually the tetrahedral F 4 3m.. Normal spinel structures are usually cubic close-packed oxides with eight tetrahedral and four octahedral sites per formula unit. The tetrahedral spaces are smaller than the octahedral spaces. B ions occupy half the
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Spinel conversion rate is important in understanding the spinel formation mechanism. The spinel conversion rates of experimental compositions are shown in Fig. 2. It can be seen that K4 has the highest spinel conversion rate at all temperatures. K1 follows as the the second highest in conversion rate while K2 and K3 exhibit the least
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The space group for a spinel group mineral may be Fd 3 m (the same as for diamond) but in some cases (such as spinel itself MgAl 2 O 4) it is actually the tetrahedral F 4 3m.. Normal spinel structures are usually cubic close-packed oxides with eight tetrahedral and four octahedral sites per formula unit. The tetrahedral spaces are smaller than the octahedral spaces. B ions occupy half the
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microstructure of alumina-spinel and alumina-magnesia ladle castables after a corrosion test using a rotary furnace. Tab. 1 gives the mass composition of these castables MA1 and MA2 use pre-reacted sintered spinel whilst castables M1 and M2 contain a sintered MgO which reacts with alumina to form in-situ spinel after firing.
Get PriceCorrosion mechanisms processesThe Fabricator
Corrosion control processes stop the flow of electrons or disrupt the chemical reaction at the cathode or anode. Rust Requirements. Three components or constituents are necessary for rust to form A cell consisting of a cathode and an anode. Moisture which provides a pathway for current flow.
Get PriceMetal Dusting Corrosion and Mechanics of Materials
Apr 21 2016 · The composition of the oxide scale is important in metal dusting corrosion. Cr 2 O 3 is a better phase than spinel to resist metal dusting since spinel can be reduced. If alloys can generate more Cr 2 O 3 and less spinel on the surface their abilities to resist metal dusting will increase. Therefore alloys with more Cr and less Fe content
Get PriceBASIC MECHANISMS OF CORROSION AND CORROSION
BASIC MECHANISMS OF CORROSION AND CORROSION CONTROL FOR WATER AND WASTEWATER SYSTEMS Graham E.C. Bell Ph.D. P.E. • Dominated by Formation of Sulfuric Acid "Indirect" Impact of Regulations on Corrosion H 2 S crown 210 ppm pH 3
Get PriceA STUDY ON SPINEL FORMATION AND SINTERING
Spinel conversion rate is important in understanding the spinel formation mechanism. The spinel conversion rates of experimental compositions are shown in Fig. 2. It can be seen that K4 has the highest spinel conversion rate at all temperatures. K1 follows as the the second highest in conversion rate while K2 and K3 exhibit the least
Get PriceCorrosion of spinel clinker by CaO–Al2O3–SiO2 ladle slag
A two-fold mechanism has been proposed to explain the good anti-corrosion performance of MgO-Al 2 O 3 . First the MgAl 2 O 4 spinel that forms in this material following a reaction between MgO
Get PriceCorrosion Inhibitors Principles Mechanisms and Applications
Corrosion InhibitorsPrinciples Mechanisms and Applications •the inhibitor leads a formation of a film by oxide protection of the base metal •the inhibitor reacts with a potential corrosive component present in aqueous media and the product is a complex. 4 14 15 1.2. Historic review
Get PriceCorrosion of high alumina spinel castables by steel ladle
Jul 18 2013 · The application of high alumina materials with additions of spinel and/or spinel forming magnesia as wear linings in steel ladles has increased in recent years. Corrosion of high alumina spinel castables by steel ladle slag The influences of mechanical properties and chemical composition on the wear mechanism are discussed. Although the
Get PriceEight forms of corrosion
Eight Forms of Corrosion by Fontana Greene 1967 The idea of describing the various ways corrosion can damage metals by it appearance had be used by many before Fontana and Greene coauthored their famous book in 1967.McKay and Worthington were already discussing various forms of corrosion in their 1936 book on corrosion. following Alan Pollitt in his own book published thirteen
Get PriceCORROSION-INHIBITIVE EFFECTS OF SPINEL TYPE PIGMENTS
represented by the corrosion of steel plate in clean distilled water. The results given in Table 4 show clearly different efficiencies of the spinel pigments investigated. It is of course necessary to consider that these results inform only on the part of potential inhibition mechanism of anticorrosive spinel
Get PriceCORROSION-INHIBITIVE EFFECTS OF SPINEL TYPE PIGMENTS
represented by the corrosion of steel plate in clean distilled water. The results given in Table 4 show clearly different efficiencies of the spinel pigments investigated. It is of course necessary to consider that these results inform only on the part of potential inhibition mechanism of anticorrosive spinel
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